The field of the present invention is down-well fluid pumping systems to remove fluid from oil wells, particularly wells wherein oil recovery is by means of an endless oil accumulating chain.
Viscous oil may be recovered from certain oil wells by means of an endless oil accumulating chain having a loop portion suspended into the oil producing region of the well. Ideally, oil flows out of the surrounding oil producing strata into the bottom portion of the well at a rate sufficient to permit oil recovery by the oil accumulating chain without excessive well draw-down. Often, however, water is associated with oil production. This water tends to separate out and form a layer below the oil, thus occasionally preventing oil from flowing into the well a preferred rate. It then becomes necessary, if efficient oil recovery is to be achieved, to pump the separated water from the bottom portion of the well. For this purpose, pump means must be employed which are capable of pumping water from well depths in excess of 1,000 feet. At the same time such pump means must be operable in conjunction with the oil accumulating chain without interfering with chain operation. Lastly, it is desirable that such pump means also be relatively inexpensive to manufacture, install, operate and maintain.